Ultra-thin membranes can be used for a wide variety of applications including use as nanosieves and nano-filters. Tong et al., “Silicon Nitride Nanoseive Membrane,” Nano Lett 4:283-287 (2004); Lee et al., “Antibody-Based Bio-Nanotube Membranes for Enantiomeric Drug Separations,” Science 296:2198-2200 (2002). Membranes can also be used for biological co-cultures, however, current methods of biological co-culturing employ relatively thick membranes, on the order of several hundred nanometers, having relatively large pores, also on the order of several hundred nanometers in diameter. In some instances, prior art silicon nitride membranes require the deposition of collagen. Ma et al., “An Endothelial and Astrocyte Co-culture Model of the Blood-brain Barrier Utilizing an Ultra-thin, Nanofabricated Silicon Nitride Membrane,” Lab on a Chip 5:74-85 (2005).
There is a need for a culture device that allows for tighter control of cellular contact and molecular interaction across the membrane. Specifically, in some instances it would be desirable to obtain a culturing device that can promote or restrict cell-to-cell contact, promote or restrict transfer of signaling molecules across the membrane, restrict signaling molecules based on size, restrict signaling molecules based on their charge, detect low abundance molecular species, and/or allow for imaging of cells on either side of the membrane.
The present invention is directed to overcoming these and other deficiencies in the art.